This is what you said:

While that may be partly true, (also likely) depending on the county you're located, they're not able to revoke the license though.

The same is true for Steam, laws are laws

So in this specific case you having the files makes a world of difference.

You also have the files if you downloaded them on Steam. What's important is whether those files can be used on their own or if they're protected by some form of DRM. If the files can be used on their own it doesn't matter if you got them from Steam, GoG or a physical disc. If on the other hand the files are DRM protected you having them is useless, whoever controls the DRM controls your files, again regardless of where you got the files from.